Multilayer Graphene Broadband Terahertz Modulators with Flexible Substrate

  • Emine Kaya
  • Nurbek Kakenov
  • Hakan Altan
  • Coskun Kocabas
  • Okan EsenturkEmail author


Fabrication of terahertz modulators as simple devices with high modulation depth across a broad bandwidth is still very challenging. In this study, four different chemical vapor deposition grown multilayer graphene (MLG) modulators based on MLG/ionic liquid/gold sandwich structures have been investigated. Flexible substrates (PVC and PE) were chosen as host materials, and devices were fabricated with three different thicknesses. The resultant MLG devices can be operated at low voltages between 0 and 3.4 V providing nearly complete modulation between 0.2 and 1.5 THz with low insertion losses. Even with such low gate voltages, the devices have been doped significantly inducing 7–11-fold improvement in their sheet conductivities depending on device thickness. In addition, sheet conductivity has been improved more than three times as the graphene layer number increased from 30 to 100. With the demonstration of promising device performances, the proposed modulators can be potential candidates for applications in terahertz and related optoelectronic technologies.


Attenuators Filters Terahertz optics Integrated photonics 


Funding Information

This research was supported by Türkiye Bilimsel ve Teknolojik Arastirma Kurumu-TUBITAK. (Scientific and Technological Research Council of Turkey). E.K. and O.E. acknowledge funding from TUBITAK grant 111T393. N.K., H.A., and C.K. acknowledge funding from TUBITAK grant 114F379.


  1. 1.
    K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, and A. A. Firsov, Science. 306, 666 (2004).CrossRefGoogle Scholar
  2. 2.
    B. Sensale-Rodriguez, R. Yan, M. M. Kelly, T. Fang, K. Tahy, W. S. Hwang, D. Jena, L. Liu, and H. G. Xing, Nat. Commun. 3, 780 (2012).CrossRefGoogle Scholar
  3. 3.
    B. Sensale-Rodriguez, R. Yan, S. Rafique, M. Zhu, W. Li, X. Liang, D. Gundlach, V. Protasenko, M. M. Kelly, D. Jena, L. Liu, and H. G. Xing, Nano Lett. 12, 4518 (2012).CrossRefGoogle Scholar
  4. 4.
    I. Maeng, S. Lim, S. J. Chae, Y. H. Lee, H. Choi, and J.-H. Son, Nano Lett. 12, 551 (2012).CrossRefGoogle Scholar
  5. 5.
    J. Lloyd-Hughes and T.-I. Jeon, J. Infrared, Millimeter, Terahertz Waves 33, 871 (2012).CrossRefGoogle Scholar
  6. 6.
    L. Ren, Q. Zhang, J. Yao, Z. Sun, R. Kaneko, Z. Yan, S. Nanot, Z. Jin, I. Kawayama, M. Tonouchi, J. M. Tour, and J. Kono, Nano Lett. 12, 3711 (2012).CrossRefGoogle Scholar
  7. 7.
    H. T. Chen, W. J. Padilla, J. M. O. Zide, A. C. Gossard, A. J. Taylor, and R. D. Averitt, Nature 444, 597 (2006).CrossRefGoogle Scholar
  8. 8.
    T. Kleine-Ostmann, K. Pierz, G. Hein, P. Dawson, M. Marso, and M. Koch, J. Appl. Phys. 105, 93707 (2009).CrossRefGoogle Scholar
  9. 9.
    A. Locatelli, G. E. Town, and C. De Angelis, IEEE Trans. Terahertz Sci. Technol. 5, 351 (2015).CrossRefGoogle Scholar
  10. 10.
    J. E. Heyes, W. Withayachumnankul, N. K. Grady, D. R. Chowdhury, A. K. Azad, and H.-T. Chen, Appl. Phys. Lett. 105, 181108 (2014).CrossRefGoogle Scholar
  11. 11.
    B. Sensale-Rodriguez, T. Fang, R. Yan, M. M. Kelly, D. Jena, L. Liu, and H.(Grace) Xing, Appl. Phys. Lett. 99, 113104 (2011).CrossRefGoogle Scholar
  12. 12.
    N. Kakenov, O. Balci, T. Takan, V. A. Ozkan, H. Altan, and C. Kocabas, ACS Photonics 3, 1531 (2016).CrossRefGoogle Scholar
  13. 13.
    W. Gao, J. Shu, K. Reichel, D. V. Nickel, X. He, G. Shi, R. Vajtai, P. M. Ajayan, J. Kono, D. M. Mittleman, and Q. Xu, Nano Lett. 14, 1242 (2014).CrossRefGoogle Scholar
  14. 14.
    F. Shi, Y. Chen, P. Han, and P. Tassin, Small 11, 6044 (2015).CrossRefGoogle Scholar
  15. 15.
    Y. Wu, C. La-O-Vorakiat, X. Qiu, J. Liu, P. Deorani, K. Banerjee, J. Son, Y. Chen, E. E. M. Chia, and H. Yang, Adv. Mater. 27, 1874 (2015).CrossRefGoogle Scholar
  16. 16.
    I. H. Baek, K. J. Ahn, B. J. Kang, S. Bae, B. H. Hong, D. I. Yeom, K. Lee, Y. U. Jeong, and F. Rotermund, Appl. Phys. Lett. 102, 191109 (2013).CrossRefGoogle Scholar
  17. 17.
    Y. Wu, X. Ruan, C.-H. Chen, Y. J. Shin, Y. Lee, J. Niu, J. Liu, Y. Chen, K.-L. Yang, X. Zhang, J.-H. Ahn, and H. Yang, Opt. Express 21, 21395 (2013).CrossRefGoogle Scholar
  18. 18.
    N. H. Shen, P. Tassin, T. Koschny, and C. M. Soukoulis, Phys. Rev. B - Condens. Matter Mater. Phys. 90, 115437 (2014).CrossRefGoogle Scholar
  19. 19.
    N. Kakenov, O. Balci, E. O. Polat, H. Altan, and C. Kocabas, J. Opt. Soc. Am. B 32, 1861 (2015).CrossRefGoogle Scholar
  20. 20.
    J. Liu, P. Li, Y. Chen, X. Song, M. Qi, W. Yang, Q. Fei, B. Zheng, H. Jiarui, H. Yang, Q. Wen, and W. Zhang, Opt. Lett. 41, 816 (2016).CrossRefGoogle Scholar
  21. 21.
    J. Y. Kim, C. Lee, S. Bae, K. S. Kim, B. H. Hong, and E. J. Choi, Appl. Phys. Lett. 98, 201907 (2011).CrossRefGoogle Scholar
  22. 22.
    E. O. Polat, O. Balcı, and C. Kocabas, Sci. Rep. 4, 6484 (2014).CrossRefGoogle Scholar
  23. 23.
    E. O. Polat, H. B. Uzlu, O. Balci, N. Kakenov, E. Kovalska, and C. Kocabas, ACS Photonics 3, 964 (2016).CrossRefGoogle Scholar
  24. 24.
    A. J. Frenzel, C. H. Lui, W. Fang, N. L. Nair, P. K. Herring, P. Jarillo-Herrero, J. Kong, and N. Gedik, Appl. Phys. Lett. 102, 113111 (2013).CrossRefGoogle Scholar
  25. 25.
    M. Qi, Y. Zhou, F. Hu, X. Xu, W. Li, A. Li, J. Bai, and Z. Ren, J. Phys. Chem. C 118, 15054 (2014).CrossRefGoogle Scholar
  26. 26.
    Y. Zhou, X. Xu, F. Hu, X. Zheng, W. Li, P. Zhao, J. Bai, and Z. Ren, Appl. Phys. Lett. 104, 51106 (2014).CrossRefGoogle Scholar
  27. 27.
    M. Orlita, C. Faugeras, P. Plochocka, P. Neugebauer, G. Martinez, D. K. Maude, A.-L. Barra, M. Sprinkle, C. Berger, W. A. de Heer, and M. Potemski, Phys. Rev. Lett. 101, 267601 (2008).CrossRefGoogle Scholar
  28. 28.
    M. Nagel, A. Safiei, S. Sawallich, C. Matheisen, T. M. Pletzer, A. A. Mewe, N. van der Borg, I. Cesar, and H. Kurz, Proc. 28th Eur. Photovolt. Sol. Energy Conf. Exhib. 856 (2013).Google Scholar

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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of ChemistryMiddle East Technical UniversityAnkaraTurkey
  2. 2.Department of PhysicsBilkent UniversityAnkaraTurkey
  3. 3.Department of PhysicsMiddle East Technical UniversityAnkaraTurkey
  4. 4.UNAM-National Nanotechnology Research CenterBilkent UniversityAnkaraTurkey

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